Discussion :: Problems on Numbers
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A two-digit number is such that the product of the digits is 8. When 18 is added to the number, then the digits are reversed. The number is:
Answer : Option B
Explanation :
Let the ten's and unit digit be x and\(\frac { 8 } {X } \)respectively.
Then,[10x +\(\frac { 8 } {X } \)]+ 18 = 10 x\(\frac { 8 } {X } \)+x
10x2 + 8 + 18x = 80 + x2
9x2 + 18x - 72 = 0
x2 + 2x - 8 = 0
(x + 4)(x - 2) = 0
x = 2.
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